Alert archive / New Jersey / Heat Advisories in 2021

Heat Advisory 7, NWS Philadelphia/Mount Holly

July 15, 20214 states

NWS Philadelphia/Mount Holly issued this heat advisory at Jul 15, 2021, 2:33 PM EDT for 4 states. It took effect at Jul 16, 2021, 12:00 PM EDT. It was in force for 31 hr.

The area

The counties it named.

The facts

Issued
Jul 15, 2021, 2:33 PM EDT (18:33 UTC)
In effect from
Jul 16, 2021, 12:00 PM EDT
Expired
Jul 17, 2021, 6:59 PM EDT
In force
31 hr
Issued by
NWS Philadelphia/Mount Holly
All 21 counties

New Castle County, DE, Caroline County, MD, Kent County, MD, Queen Anne's County, MD, Talbot County, MD, Burlington County, NJ, Camden County, NJ, Gloucester County, NJ, Hunterdon County, NJ, Mercer County, NJ, Middlesex County, NJ, Monmouth County, NJ, Morris County, NJ, Ocean County, NJ, Salem County, NJ, Somerset County, NJ, Bucks County, PA, Chester County, PA, Delaware County, PA, Montgomery County, PA, Philadelphia County, PA

The radar

The Philadelphia radar (KDIX), 64 km from the middle of the area, began a volume at 18:33 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 12:00Z, 6.6 hours before the alert went out and 219 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Washington/Dulle, VA at 12:00Z on 2021-07-15Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 226 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Washington/Dulle, VA at 12:00Z on 2021-07-15The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 16 square meters per square second.1939Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
226 J/kg
Mixed-layer CIN
-103 J/kg
Mixed-layer LCL
1124 m above ground
0-6 km bulk shear
23 kt
0-1 km storm-relative helicity
16 m²/s²
0-3 km storm-relative helicity
70 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

512 
WWUS71 KPHI 151833
NPWPHI

URGENT - WEATHER MESSAGE
National Weather Service Mount Holly NJ
233 PM EDT Thu Jul 15 2021

DEZ001-NJZ010-012-015>019-PAZ070-071-102-104-106-161000-
/O.NEW.KPHI.HT.Y.0007.210716T1600Z-210718T0000Z/
New Castle-Somerset-Middlesex-Mercer-Salem-Gloucester-Camden-
Northwestern Burlington-Delaware-Philadelphia-Eastern Chester-
Eastern Montgomery-Lower Bucks-
Including the cities of Wilmington, Somerville, New Brunswick, 
Trenton, Pennsville, Glassboro, Camden, Cherry Hill, Moorestown, 
Mount Holly, Media, Philadelphia, West Chester, Kennett Square, 
Norristown, Lansdale, Morrisville, and Doylestown
233 PM EDT Thu Jul 15 2021

...HEAT ADVISORY IN EFFECT FROM NOON FRIDAY TO 8 PM EDT
SATURDAY...

* WHAT...Heat index values up to 102 expected.

* WHERE...The urban corridor of northern Delaware, southeast
  Pennsylvania and New Jersey.  

* WHEN...From noon Friday to 8 PM EDT Saturday.

* IMPACTS...Hot temperatures and high humidity may cause heat 
  illnesses to occur.


PRECAUTIONARY/PREPAREDNESS ACTIONS...

Drink plenty of fluids, stay in an air-conditioned room, stay out
of the sun, and check up on relatives and neighbors. Young
children and pets should never be left unattended in vehicles
under any circumstances.

Take extra precautions if you work or spend time outside. When
possible reschedule strenuous activities to early morning or
evening. Know the signs and symptoms of heat exhaustion and heat
stroke. Wear lightweight and loose fitting clothing when
possible. To reduce risk during outdoor work, the Occupational
Safety and Health Administration recommends scheduling frequent
rest breaks in shaded or air conditioned environments. Anyone
overcome by heat should be moved to a cool and shaded location.
Heat stroke is an emergency! Call 9 1 1.

&&

$$

PO
4 follow-up statements
195 
WWUS71 KPHI 160801
NPWPHI

URGENT - WEATHER MESSAGE
National Weather Service Mount Holly NJ
401 AM EDT Fri Jul 16 2021

NJZ008-013-014-020-027-162115-
/O.EXB.KPHI.HT.Y.0007.210716T1600Z-210717T0000Z/
Morris-Western Monmouth-Eastern Monmouth-Ocean-
Southeastern Burlington-
Including the cities of Morristown, Freehold, Sandy Hook, 
Jackson, and Wharton State Forest
401 AM EDT Fri Jul 16 2021

...HEAT ADVISORY IN EFFECT FROM NOON TODAY TO 8 PM EDT THIS
EVENING...

* WHAT...Heat index values up to 102 expected.

* WHERE...Morris, Western Monmouth, Eastern Monmouth, Ocean and 
  Southeastern Burlington.

* WHEN...From noon today to 8 PM EDT this evening.

* IMPACTS...Hot temperatures and high humidity may cause heat
  illnesses to occur.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Drink plenty of fluids, stay in an air-conditioned room, stay out
of the sun, and check up on relatives and neighbors. Young
children and pets should never be left unattended in vehicles
under any circumstances.

Take extra precautions if you work or spend time outside. When
possible reschedule strenuous activities to early morning or
evening. Know the signs and symptoms of heat exhaustion and heat
stroke. Wear lightweight and loose fitting clothing when
possible. To reduce risk during outdoor work, the Occupational
Safety and Health Administration recommends scheduling frequent
rest breaks in shaded or air conditioned environments. Anyone
overcome by heat should be moved to a cool and shaded location.
Heat stroke is an emergency! Call 9 1 1.

&&

$$

DEZ001-NJZ010-012-015>019-PAZ070-071-102-104-106-162115-
/O.CON.KPHI.HT.Y.0007.210716T1600Z-210718T0000Z/
New Castle-Somerset-Middlesex-Mercer-Salem-Gloucester-Camden-
Northwestern Burlington-Delaware-Philadelphia-Eastern Chester-
Eastern Montgomery-Lower Bucks-
Including the cities of Wilmington, Somerville, New Brunswick, 
Trenton, Pennsville, Glassboro, Camden, Cherry Hill, Moorestown, 
Mount Holly, Media, Philadelphia, West Chester, Kennett Square, 
Norristown, Lansdale, Morrisville, and Doylestown
401 AM EDT Fri Jul 16 2021

...HEAT ADVISORY REMAINS IN EFFECT FROM NOON TODAY TO 8 PM EDT
SATURDAY...

* WHAT...Heat index values up to 102 expected.

* WHERE...Portions of central, northern and southern New Jersey, 
  southeast Pennsylvania and northern Delaware.

* WHEN...From noon today to 8 PM EDT Saturday.

* IMPACTS...Hot temperatures and high humidity may cause heat 
  illnesses to occur.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Drink plenty of fluids, stay in an air-conditioned room, stay out
of the sun, and check up on relatives and neighbors. Young
children and pets should never be left unattended in vehicles
under any circumstances.

Take extra precautions if you work or spend time outside. When
possible reschedule strenuous activities to early morning or
evening. Know the signs and symptoms of heat exhaustion and heat
stroke. Wear lightweight and loose fitting clothing when
possible. To reduce risk during outdoor work, the Occupational
Safety and Health Administration recommends scheduling frequent
rest breaks in shaded or air conditioned environments. Anyone
overcome by heat should be moved to a cool and shaded location.
Heat stroke is an emergency! Call 9 1 1.

&&

$$

Staarmann
320 
WWUS71 KPHI 161906
NPWPHI

URGENT - WEATHER MESSAGE
National Weather Service Mount Holly NJ
306 PM EDT Fri Jul 16 2021

NJZ008-013-014-020-027-171200-
/O.EXT.KPHI.HT.Y.0007.000000T0000Z-210718T0000Z/
Morris-Western Monmouth-Eastern Monmouth-Ocean-
Southeastern Burlington-
Including the cities of Morristown, Freehold, Sandy Hook, 
Jackson, and Wharton State Forest
306 PM EDT Fri Jul 16 2021

...HEAT ADVISORY NOW IN EFFECT UNTIL 8 PM EDT SATURDAY...

* WHAT...Heat index values up to 100 to 102 are expected.

* WHERE...New Jersey's urban corridor and nearby counties.

* WHEN...Until 8:00 PM Saturday.

* IMPACTS...Hot temperatures and high humidity levels may result 
  in heat related health issues for some individuals.

* ADDITIONAL DETAILS...The highest heat index values will occur 
  from mid afternoon until early evening.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Drink plenty of fluids, stay in an air-conditioned location, stay
out of the sun, and check on elderly relatives and neighbors. 
Young children and pets should never be left unattended in a 
vehicle under any circumstance.

Take extra precautions if you work or spend time outside. When 
possible, reschedule strenuous activities to the early morning or 
late evening hours. Know the signs and symptoms of heat exhaustion
and heat stroke. Wear lightweight and loose fitting clothing. To 
reduce your risk during outdoor work, the Occupational Safety and 
Health Administration recommends scheduling frequent rest breaks 
in a shaded or air conditioned environment. Anyone overcome by 
heat should be moved to a cool shaded location. Heat stroke is an 
emergency! Call 9 1 1.

&&

$$

DEZ001-NJZ010-012-015>019-PAZ070-071-102-104-106-171200-
/O.CON.KPHI.HT.Y.0007.000000T0000Z-210718T0000Z/
New Castle-Somerset-Middlesex-Mercer-Salem-Gloucester-Camden-
Northwestern Burlington-Delaware-Philadelphia-Eastern Chester-
Eastern Montgomery-Lower Bucks-
Including the cities of Wilmington, Somerville, New Brunswick, 
Trenton, Pennsville, Glassboro, Camden, Cherry Hill, Moorestown, 
Mount Holly, Media, Philadelphia, West Chester, Kennett Square, 
Norristown, Lansdale, Morrisville, and Doylestown
306 PM EDT Fri Jul 16 2021

...HEAT ADVISORY REMAINS IN EFFECT UNTIL 8 PM EDT SATURDAY...

* WHAT...Heat index values up to 100 to 102 are expected.

* WHERE...The urban corridor of New Jersey, southeastern 
  Pennsylvania, northern Delaware and nearby counties.

* WHEN...Until 8:00 PM Saturday.

* IMPACTS...Hot temperatures and high humidity levels may result 
  in heat related health issues for some individuals.

* ADDITIONAL DETAILS...The highest heat index values will occur 
  from mid afternoon until early evening.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Drink plenty of fluids, stay in an air-conditioned location, stay
out of the sun, and check on elderly relatives and neighbors. 
Young children and pets should never be left unattended in a 
vehicle under any circumstance.

Take extra precautions if you work or spend time outside. When 
possible, reschedule strenuous activities to the early morning or 
late evening hours. Know the signs and symptoms of heat exhaustion
and heat stroke. Wear lightweight and loose fitting clothing. To 
reduce your risk during outdoor work, the Occupational Safety and 
Health Administration recommends scheduling frequent rest breaks 
in a shaded or air conditioned environment. Anyone overcome by 
heat should be moved to a cool shaded location. Heat stroke is an 
emergency! Call 9 1 1.

&&

$$

Iovino
313 
WWUS71 KPHI 170654
NPWPHI

URGENT - WEATHER MESSAGE
National Weather Service Mount Holly NJ
254 AM EDT Sat Jul 17 2021

NJZ009-PAZ101-103-105-180000-
/O.EXA.KPHI.HT.Y.0007.000000T0000Z-210718T0000Z/
Hunterdon-Western Chester-Western Montgomery-Upper Bucks-
Including the cities of Flemington, Honey Brook, Oxford, 
Collegeville, Pottstown, Chalfont, and Perkasie
254 AM EDT Sat Jul 17 2021

...HEAT ADVISORY IN EFFECT UNTIL 8 PM EDT THIS EVENING...

* WHAT...Heat index values up to 101.

* WHERE...In New Jersey, Hunterdon. In Pennsylvania, Western 
  Chester, Western Montgomery and Upper Bucks.

* WHEN...Until 8 PM EDT this evening.

* IMPACTS...Hot temperatures and high humidity may cause heat
  illnesses to occur.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Drink plenty of fluids, stay in an air-conditioned room, stay out
of the sun, and check up on relatives and neighbors. Young
children and pets should never be left unattended in vehicles
under any circumstances.

Take extra precautions if you work or spend time outside. When
possible reschedule strenuous activities to early morning or
evening. Know the signs and symptoms of heat exhaustion and heat
stroke. Wear lightweight and loose fitting clothing when
possible. To reduce risk during outdoor work, the Occupational
Safety and Health Administration recommends scheduling frequent
rest breaks in shaded or air conditioned environments. Anyone
overcome by heat should be moved to a cool and shaded location.
Heat stroke is an emergency! Call 9 1 1.

&&

$$

MDZ012-015-019-020-180000-
/O.EXA.KPHI.HT.Y.0007.000000T0000Z-210718T0000Z/
Kent MD-Queen Annes-Talbot-Caroline-
Including the cities of Chestertown, Centreville, Easton, 
and Denton
254 AM EDT Sat Jul 17 2021

...HEAT ADVISORY IN EFFECT UNTIL 8 PM EDT THIS EVENING...

* WHAT...Heat index values up to 106.

* WHERE...Kent MD, Queen Annes, Talbot and Caroline.

* WHEN...Until 8 PM EDT this evening.

* IMPACTS...Hot temperatures and high humidity may cause heat
  illnesses to occur.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Drink plenty of fluids, stay in an air-conditioned room, stay out
of the sun, and check up on relatives and neighbors. Young
children and pets should never be left unattended in vehicles
under any circumstances.

Take extra precautions if you work or spend time outside. When
possible reschedule strenuous activities to early morning or
evening. Know the signs and symptoms of heat exhaustion and heat
stroke. Wear lightweight and loose fitting clothing when
possible. To reduce risk during outdoor work, the Occupational
Safety and Health Administration recommends scheduling frequent
rest breaks in shaded or air conditioned environments. Anyone
overcome by heat should be moved to a cool and shaded location.
Heat stroke is an emergency! Call 9 1 1.

&&

$$

DEZ001-NJZ008-010-012>015-017>020-027-PAZ070-071-102-104-106-
180000-
/O.CON.KPHI.HT.Y.0007.000000T0000Z-210718T0000Z/
New Castle-Morris-Somerset-Middlesex-Western Monmouth-
Eastern Monmouth-Mercer-Gloucester-Camden-Northwestern Burlington-
Ocean-Southeastern Burlington-Delaware-Philadelphia-
Eastern Chester-Eastern Montgomery-Lower Bucks-
Including the cities of Wilmington, Morristown, Somerville, 
New Brunswick, Freehold, Sandy Hook, Trenton, Glassboro, Camden, 
Cherry Hill, Moorestown, Mount Holly, Jackson, 
Wharton State Forest, Media, Philadelphia, West Chester, 
Kennett Square, Norristown, Lansdale, Morrisville, and Doylestown
254 AM EDT Sat Jul 17 2021

...HEAT ADVISORY REMAINS IN EFFECT UNTIL 8 PM EDT THIS EVENING...

* WHAT...Heat index values up to 103.

* WHERE...Portions of central, northern and southern New Jersey, 
  southeast Pennsylvania and northern Delaware.

* WHEN...Until 8 PM EDT this evening.

* IMPACTS...Hot temperatures and high humidity may cause heat
  illnesses to occur.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Drink plenty of fluids, stay in an air-conditioned room, stay out
of the sun, and check up on relatives and neighbors. Young
children and pets should never be left unattended in vehicles
under any circumstances.

Take extra precautions if you work or spend time outside. When
possible reschedule strenuous activities to early morning or
evening. Know the signs and symptoms of heat exhaustion and heat
stroke. Wear lightweight and loose fitting clothing when
possible. To reduce risk during outdoor work, the Occupational
Safety and Health Administration recommends scheduling frequent
rest breaks in shaded or air conditioned environments. Anyone
overcome by heat should be moved to a cool and shaded location.
Heat stroke is an emergency! Call 9 1 1.

&&

$$

NJZ016-180000-
/O.CON.KPHI.HT.Y.0007.000000T0000Z-210718T0000Z/
Salem-
Including the city of Pennsville
254 AM EDT Sat Jul 17 2021

...HEAT ADVISORY REMAINS IN EFFECT UNTIL 8 PM EDT THIS EVENING...

* WHAT...Heat index values up to 105.

* WHERE...Salem.

* WHEN...Until 8 PM EDT this evening.

* IMPACTS...Hot temperatures and high humidity may cause heat
  illnesses to occur.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Drink plenty of fluids, stay in an air-conditioned room, stay out
of the sun, and check up on relatives and neighbors. Young
children and pets should never be left unattended in vehicles
under any circumstances.

Take extra precautions if you work or spend time outside. When
possible reschedule strenuous activities to early morning or
evening. Know the signs and symptoms of heat exhaustion and heat
stroke. Wear lightweight and loose fitting clothing when
possible. To reduce risk during outdoor work, the Occupational
Safety and Health Administration recommends scheduling frequent
rest breaks in shaded or air conditioned environments. Anyone
overcome by heat should be moved to a cool and shaded location.
Heat stroke is an emergency! Call 9 1 1.

&&

$$

Staarmann
204 
WWUS71 KPHI 172259
NPWPHI

URGENT - WEATHER MESSAGE
National Weather Service Mount Holly NJ
659 PM EDT Sat Jul 17 2021

DEZ001-MDZ012-015-019-020-NJZ008>010-012>020-027-PAZ070-071-
101>106-180000-
/O.CAN.KPHI.HT.Y.0007.000000T0000Z-210718T0000Z/
New Castle-Kent MD-Queen Annes-Talbot-Caroline-Morris-Hunterdon-
Somerset-Middlesex-Western Monmouth-Eastern Monmouth-Mercer-Salem-
Gloucester-Camden-Northwestern Burlington-Ocean-
Southeastern Burlington-Delaware-Philadelphia-Western Chester-
Eastern Chester-Western Montgomery-Eastern Montgomery-Upper Bucks-
Lower Bucks-
Including the cities of Wilmington, Chestertown, Centreville, 
Easton, Denton, Morristown, Flemington, Somerville, 
New Brunswick, Freehold, Sandy Hook, Trenton, Pennsville, 
Glassboro, Camden, Cherry Hill, Moorestown, Mount Holly, Jackson,
Wharton State Forest, Media, Philadelphia, Honey Brook, Oxford, 
West Chester, Kennett Square, Collegeville, Pottstown, 
Norristown, Lansdale, Chalfont, Perkasie, Morrisville, 
and Doylestown
659 PM EDT Sat Jul 17 2021

...HEAT ADVISORY IS CANCELLED...

Temperatures and heat index values are dropping with the loss of 
daytime heating and showers and thunderstorms around the area. 
Therefore, the Heat Advisory will be cancelled.

$$

Nearby

Heat Advisories in New Jersey, 2021Heat Advisories in Pennsylvania, 2021Heat Advisories in Maryland, 2021Every heat advisory in 2021

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.